1. Field of the Invention
The present invention generally relates to the mounting of windows in a frame, particularly to the mounting of panes or windshields of a vehicle, e.g. an automobile, in the body frame work. The invention provides a pane or windshield ready to be mounted comprising, along its edges, a first profiled bead of adhesive material already cured. This first bead is elastic but not plastically deformable. The first bead is provided with a second bead of plastically deformable not yet cured adhesive material consisting of a substance chemically compatible to the material of the first bead.
2. Prior Art
Conventionally, a vehicle pane or windshield is fixed in the frame of a vehicle body by means of a double U-profile frame member made of rubber or a similarly elastically resilient material. On the one hand, the edge of the pane or windshield is received in a first recess of the double U-profile facing the interior of the double U-profile frame member, and on the other hand, the second recess directed away from the double U-profile frame member engages the edges of a body frame, of a flange or the like of the vehicle body to thereby fix the pane or windshield in its desired position.
More and more, to so-called direct mounting of vehicle panes or windshields is used in which an edge portion of the pane or windshield is glued to the edges of a body frame, of a flange or the like e.g. of a vehicle body by means of a suitable adhesive material. The known methods may be divided into the following three groups:
1. Methods in which the pane or windshield is delivered to the car manufacturer in a "pure" form, in some cases equipped with a layer of material along its edges which is impermeable to light and UV-radiation and/or with a layer of primer material. No further preparation of the pane or windshield glass has been effected. Thereby, the mounting adhesive material is applied immediately in situ, i.e. just before mounting the pane or windshield into the car body by gluing.
2. Methods in which the pane or windshield is provided with a first bead of adhesive material, if appropriate also using a light- or UV-impermeable layer and/or a primer layer. The application of this first bead is performed separatly from the car manufacturing plant or from the assembling line. The first bead is fully cured. The real mounting adhesive material is again applied immediately prior to mounting the pane or windshield into the frame of the car body.
3. Methods in which the pane or windshield is fully prepared, ready to be mounted, distantly from the assembling line and probably some time prior to having to be mounted. Thereby, the adhesive bead required for gluing the pane or windshield into the frame of the car body, consisting of a polyurethane material curing under the influence of moisture, is applied along the edges of the pane or windshield, and the pane or windshield thus prepared, ready to be mounted, is sealed in air tight foil material to enable the pane or windshield to be stored during a certain period without curing of the adhesive material.
All three methods mentioned hereinabove can not provide an optimal solution. The reason is that in all cases considerable time- and labour-consuming operations have to be performed to prepare the pane or windshield for mounting. These operations have to be done immediately in situ, e.g. at the assembly line for an automobile. Particularly, in the case of the methods 1. and 2. explained hereinbefore, the pane or windshield probably has to be cleaned along its edge portion and the adhesive material must be applied to the pane or windshield and/or to the edge portion of the frame, of the flange or the like of a car body. In the case of method 3. explained hereinbefore, a large sized sealing foil must be carefully removed in order not to damage the already applied adhesive material and the large and expensive sealing foil must be removed from the work place and destroyed or recycled in some way.
The purpose of the present invention is, generally speaking and in the widest sense, to improve a method of the category 3. explained hereinbefore and to provide an improved ready-to-mount vehicle pane or windshield.
A method relating to the aforementioned category 1. is known, for instance, from the published German Patent Application P No. 27 30 831 and must not be discussed in detail here. The disadvantages of the methods according to category 1. are well known in the art; particularly disadvantageous is that the edge portion onto which the adhesive material is applied has to be cleaned just prior to applying the adhesive material, the time-consuming applying of the adhesive material bead which must be performed with the utmost accuracy and the short period of time provided to perform these operation which is directly dependent from the operation cycle set for the assembly line.
The method according to the published German Patent Application P No. 34 09 960 relates to the adhesive bonding of vehicle panes or windshields into the frame of a vehicle body whereby the adhesive material is applied directly at the assembly line; thus, this publication belongs to the aforementioned category 2. According to the disclosure of this publication two beads of compatible adhesive material are applied to the pane or windshield in two separate phases. In the first phase, a profiled bead of adhesive material is applied onto an edge region of the pane or windshield and subsequently cured whereby one or more primer layers may be provided between said profiled bead and the surface of the pane or windshield. Thus, in the second phase when the second bead is applied, the first profiled bead forms an intermediate body between the pane or windshield and the second bead, said intermediate body being no longer plastically deformable.
While the profiled first bead applied onto the pane or windshield is already cured when the pane or windshield is to be mounted, the second bead is applied at the assembly line immediately before mounting the pane or windshield.
It is admitted that certain minor advantages result from a method disclosed in the two aforementioned German Patent Applications, especially with respect to the application of the second bead of adhesive material which is the real bonding bead; however, many of the disadvantages discussed in connection with the proceeding according to category 1. hereinbefore are nevertheless existing.
The only publication known to the inventors which belongs to the aforementioned category 3., i.e. a method in which the pane or windshield is prepared ready to be mounted into a car body, is the published German Patent Application P No. 36 38 449. According to the disclosure of this publication, the application of the adhesive material onto the pane or windshield is performed independently with regard to time and place of the car to which the pane or windshield has to be mounted. An adhesive material is used which cures under the influence of atmospheric moisture. The adhesive material is protected from any moisture during its application or immediately thereafter until to the moment of mounting the pane or windshield into the car by a combination of a superposition of a dry protection gas with a chemical drying agent and/or a physical drying process.
The pane or windshield with the applied adhesive material is singly or in groups of several units packaged in an environment free of moisture such that the adhesive material can not contact any moisture during the subsequent storage or transport.
Preferably, the pane or windshield is sealed between air tight foils such that the foil have a certain distance from the adhesive material. Then, the air enclosed in this pane or windshield package is evacuated and the package is filled with a protection gas. The pressure on the pane or windshield and the adhesive material can correspond to the atmospheric environment pressure such that even soft parts of the package are not deformed.
In the place where the pane or windshield is to be mounted, the still packed pane or windshield must be ventilated in order to enable the foil to be removed. In order to support this operation the pane or windshield packaging can comprise means for the ventilating of the packaging at a later date. For instance, suitable ventilating tubes may be provided in the packaging. The ventilating operation can be performed with air having a high humidity to displace the protection gas. If a certain time period has gone before the foil is removed the curing of the adhesive material can be accelerated.
Essential is, consequently, that the pane or windshield is readily prepared by means of cleaning agents, primers and adhesive material separately with regard to time and place from the assembly line, from the repair shop or the like, and that the adhesive material is perfectly sealed against moisture.
It is true that a proceeding in line with the teaching of the aforementioned publication removes the need to apply the real mounting adhesive material bead in situ, e.g. at the assembly line. On the other hand, however, it is disadvantageous that the pane or windshield prepared in accordance with the teaching of the aforementioned publication must firstly be prepared for the ventilating operation, that usually a certain time has to pass after the ventilation operation, that the unpacking of the pane or windshield is cumbersome and time-consuming, and that the voluminous packaging material has to be removed from the work station and destroyed or recycled. Moreover, the aforementioned publication does not disclose how an unintentional and highly unwelcome escaping of the still pasty adhesive material over the edge of the pane or windshield and/or into the viewing area of the pane or windshield is avoided.